Protein Synthesis

By. Anna Heitzenrater

TACTCTGGCATCACT

ATGAGACCGTAGTGA

CELL

Nucleus

Cytoplasm

CELL

Nucleus

Cytoplasm

CELL

Nucleus

Cytoplasm

CELL

Nucleus

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Nucleus

Cytoplasm

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Nucleus

Cytoplasm

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Nucleus

Cytoplasm

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

Nucleus

RNA Polymerase

Promoter Region

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

Nucleus

RNA Polymerase

mRNA strand

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

Nucleus

RNA Polymerase

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

Nucleus

RNA Polymerase

AU

G

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

Nucleus

A U G A GA

RNA Polymerase

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

Nucleus

RNA Polymerase

A U G A G AC C G

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

Nucleus

RNA Polymerase

A U G A G AC C G U A G

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

Nucleus

A U G A G AC C G U A G UG A

RNA Polymerase

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

Nucleus

A U G A G AC C G U A G UG A

Termination Sequence

RNA Polymerase

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

Nucleus

A U G A G AC C G U A G UG A

Termination Sequence

RNA Polymerase

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

Nucleus

G A C C G U A G U G A

Nuclear Pore

Note: The mRNA must leave the nucleus through the nuclear pores to reach the ribosomes.

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

U G A G A C C G U A G U G A

Nucleus

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

A U G A G A C C G U A G U G A

Nucleus

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

A U G A G A C C G U A G U G A

Nucleus

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

A U G A G A C C G U A G U G A

Nucleus

TACTCTGGCATCACT

ATGAGACCGTAGTGA

Cytoplasm

A U G A G A C C G U A G U G A

Nucleus

Nucleus

Cytoplasm Ribosomes

Nucleus

Cytoplasm

mRNA strand

Ribosomes

Nucleus

Cytoplasm Ribosomes

Nucleus

Cytoplasm Ribosomes

Nucleus

Cytoplasm Ribosomes

Nucleus

Cytoplasm Ribosomes

Nucleus

Cytoplasm Ribosomes

A U G A G A C C G U A G U G A

A U G A G A C C G U A G U G A

Ribosome: large subunit

Small subunit

A U G A G A C C G U A G U G A

tRNA

Anti-codon

Amino acid

Cytoplasm

U AC

Codon

A U G A G A C C G U A G U G A

Cytoplasm

U A C

Start Codon

A U G A G A C C G U A G U G A

Cytoplasm

U A C

U C U

A U G A G A C C G U A G U G A

Cytoplasm

U A C

U C U

A U G A G A C C G U A G U G A

Cytoplasm

U A C U C

U

A U G A G A C C G U A G U G A

Cytoplasm

U A C U C

U

A U G A G A C C G U A G U G A

Cytoplasm

U C U

Peptide Bond

A U G A G A C C G U A G U G A

Cytoplasm

U C U

G G C

A U G A G A C C G U A G U G A

Cytoplasm

U C U

G G C

A U G A G A C C G U A G U G A

Cytoplasm

U C U G G

C

A U G A G A C C G U A G U G A

Cytoplasm

U C U

G G C

A U G A G A C C G U A G U G A

Cytoplasm

G G C

A U C

A U G A G A C C G U A G U G A

Cytoplasm

G G C

A U C

A U G A G A C C G U A G U G A

Cytoplasm

G G C A

U C

A U G A G A C C G U A G U G A

Cytoplasm

G G C A

U C

A U G A G A C C G U A G U G A

Cytoplasm

G G C

A U C

A U G A G A C C G U A G U G A

Cytoplasm

A U C

A U C

A U G A G A C C G U A G U G A

Cytoplasm

A U C

A C U

Note: The stop codon does not make an amino acid.

Stop Codon

A U G A G A C C G U A G U G A

Cytoplasm

A U C

A C

U

A U G A G A C C G U A G U G A

Cytoplasm

A C U

Stop Codon

Polypeptide Chain

A U G A G A C C G U A G U G A

Cytoplasm

A C U

A U G A G A C C G U A G U G A

Cytoplasm

Note: The polypeptide chain then forms into a three-dimensional figure (tertiary structure).

SummaryFirst, the enzyme RNA polymerase comes in. It unwinds the double helix and adds the complementary nucleotides, there is also a complementary mRNA strand that forms. But, since it is RNA, the thymine is replaced with uracil. Then, the double helix closes back up after RNA polymerase goes through. The mRNA exits through the nuclear pores and travels through the cytoplasm to get to the ribosomes. Once in the ribosomes, the large and small subunit of the ribosomes bind with the mRNA. The ribosome begins at the start codon, that is always AUG. As the ribosome moves down the mRNA strand, the tRNA molecule, with the correct anti-codon sequence, then binds onto the codon. As the ribosome keeps on moving, the amino acids from the previous tRNA falls off and attaches to the next amino acid. This forms a peptide bond and the tRNA molecule falls off. This continues until the ribosome reaches the stop codon, the codon either has a sequence of UAA, UAG, or UGA. The polypeptide chain, that was formed from the amino acid, then folds into a three dimensional figure, also known as its tertiary structure.